Watch This Woman Pull a Giant Blackhead Out of Her Belly Button

Jamie Davis is strangely calm when the tweezers near her belly button. She had noticed a strange growth forming in her navel nine months earlier, but left it alone. When her sister Lacey saw the growing mass, she thought it was hair. She decided to remove it with tweezers and found a giant blackhead, Mashable reports.

"Umboliths (also known as omphalolith, omphalith, or omphalokeratolith) are not really common," says dermatologist Dr. Sejal Shah. "They occur due to an accumulation of sebum and keratin in the belly button, and over time, this hardens into a hard, stone-like mass in the belly button (umbilicus). Why some people get them is not known, but they are often associated with poor hygiene or a deep belly button."

Dr. Shah explains that blackheads, the common variety that develop on faces, are caused by blocked hair follicles. The keratin and sebum become oxidized to appear black. Umboliths, on the other hand, are not caused by blocked hair follicles.

"Honestly, I was scared to pull it out of my belly button, but my sister insisted," Jamie tells Teen Vogue." She said it absolutely had to come out. I haven't seen a doctor about it because we're pretty positive of what it is."

Dr. Shah said that umboliths tend to be hard and impacted in the belly button, and usually won't come out with tweezers alone. "Also you the run the risk of leaving portion in the belly button, or causing infection and skin damage," she adds. "Usually, it's best to see a doctor who can gently dilate the belly button and extract the mass."

Umboliths aren't dangerous and often go unnoticed until they become infected or inflamed, or — as in Jamie's case — hairs become trapped in them.